Recently I've been trying to find a way to extract instrument samples out of Neo Geo games to use in a DAW - I was wondering if anyone had any idea how to achieve this.

Judging from the specifications of the Neo Geo's YM2610 chip, the samples are stored as either 4-bit, 18.5khz ADPCM, or at a varying rate up to 55.5khz. I've had some sucess opening Neo Geo ROM files and VGMs in Goldwave as an ADPCM file, but the resulting playback is very distorted and impossible to be used.

Would anyone know the correct way to get the ADPCM samples out of a Neo-Geo game, or open the VGMs as the 'right kind' of ADPCM file to cut them out manually?

At first you need to know, that the YM2610 has two types of ADPCM.
The first one (which is also known as ADPCM-A) is the one that's used for most samples, because the YM2610 has 6 channels that play ADPCM-A data.
The second one (which is known as ADPCM-B) is used by the YM DELTA-T chip that's included with YM2608, YM2610 and Y8950 sound chips. There's only one channel for it, so it's not used as much.

I discussed this a little with someone called FRONT on SMSPower, but since vgmrips is now the place for such discussions, I didn't post there. But here are some links:
For converting ADPCM-A, use the attachment of this post by FRONT.
For converting ADPCM-B (or DELTA-T), use the tool I posted here.

Extracting sample data from VGMs is fairly easy:
At first search for the bytes 67 66 82 (YM2610 ADPCM A data) or 67 66 83 (YM2610 ADPCM B data).
After that there are 4 bytes (in Little Endian) that describe the data size of the sample data. Then copy the number of bytes (starting after the 4 bytes for the data size) to a new file and delete the first 8 bytes from it.
(See the VGM specification for more information.)

Now you can use one of the tools above to convert the extracted ADPCM data to standard PCM.

If you can write C programs (or you know someone that can), you can take the source of vgm_sro and modify it so that it outputs the sample start and sample end offsets instead of making a mask of used bytes.
Or you can make it even write the sample data itself.

This post, just to inform people who are interrested by ADPCM sample creation (and Ripping of course) for NeoGeo ... that a new tool with probably a Windows GUI is coming in a short time ...

Stay tuned : http://neobitz.com/ thanks you to JEFF KURTZ to come back to NeoGeo's Dev Scene after so many years !
concerning MVSTracker, the only tool to creat FM sound music for this system, the ADPCM Type A encoder was bugged ... (No sound on the real hardware) - Jeff have fixed this problem now !

Bye

_________________Fred/FRONT!

Last edited by Fred/FRONT on 2012-05-09, 11:49:27, edited 1 time in total.

I welcome Freem, who joined the VGM Rips's forum this year ... -> this is his first post in this forum:viewtopic.php?f=15&t=1934 Neo-Geo V ROM builder? -> since 2015-02-13, AJ found the solution: -> Sailor VROM

PS2: We can imagine created some VGM Homebrew (VGM conversion with M1 player) for the NeoGeo system containing only ADPCM stream...

I take the oportuny of this message to greet again ValleyBell and all VGM dev,musicians who share their productions every day on VGM Rips !! thanks a lot Guys

Regards,

in 2012, i build this ROM for DELTA-T BGM, and ask to a friend XCeL a test on the real HardwareSo -> The ValleyBell's ADPCM-B encoder is producing ALSO good output on AES ... need more feed back> https://www.youtube.com/watch?v=lvXdLXcaeSE (sound test on Real NEOGEO= AES)

Ha, nice find and congrats to Chris for finding that. That is quite fascinating. It looks like they didn't even bother with any intermediary formats, they literally just write the music as raw MML straight into the ROM.

Edit: Decided to look a little further into this and it looks their earlier games (Alpha68K hardware with YM2413 etc) has a similar MML format.

for informationThe 25 December, 2017, Blastar (the great German Homebrewer from the NeoGeo Scene) release his 'NGFX Soundbuilder'

The GUI (inspired by NeoBitz) but with new Features in comparison to 'NeoSoundBuilder beta v11', like Adpcm-B+ CDDA support and more Players-Commands, Import/Export wav and original Neo adpcm-A+B Sample). discover by yourself this great tool !!!

-To download this great tool, please visit his Blog: http://blastar.citavia.de/I hope For all vgmrips members, a very Merry Christmas and a Happy New Year filled with all the good stuff!regards

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